XRD and planktonic foraminifera abundance and isotope data for core LO09-18 spanning MIS3

Multiproxy data from core LO09-18 from the Reykjanes Ridge. Calcite content and quartz/plagioclase measured using XRD. The quartz/plagioclase ratio of North Atlantic sediments reflects the varying contribution of continental derived quartz versus that of basaltic plagioclase and can be used as a proxy for the contribution of ice-rafted detritus. Details about the measurements and interpretation can be found in https://doi.org/10.1016/S0025-3227(02)00592-3 and https://doi.org/10.1016/S0012-821X(03)00675-7.

Stable carbon and oxygen isotope ratios were measured on at least three aliquots of seven shells of N. pachyderma >150 µm using a Finnigan MAT 253 coupled to a Kiel IV device. Reproducibility of an external standard (NBS19) amounted to 0.05 ‰ and 0.03 ‰ (1 s.d.) for δ18O and δ13C, respectively.

Foraminiferal census counts of core LO09-18 were performed on the >150 µm fraction. The assemblage data were used to derive summer sea surface temperatures using weighted averaging partial least squared regression (WA-PLS) (https://doi.org/10.1007/BF00028046) and the training set of https://doi.org/10.1016/j.quascirev.2004.07.014. The modern temperature values for 10 m water depth during summer (July, August, September) for the calibration dataset were taken from the World Ocean Atlas version 2 (WOA, 1998).

Two age models are presented. The first is based on radiocarbon ages of Neogloborquadrina pachyderma. The second is a refinement of this age model and is also based on tuning the IRD (quartz/plagioclase) time series to the oxygen isotope time series of NGRIP.